<!DOCTYPE html>
<html lang="en">

<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <meta http-equiv="X-UA-Compatible" content="ie=edge">
    <title>Document</title>
</head>

<body>

</body>
<script>

    var obj1 = { name: 'jack', age: 18 };
    var obj2 = { sex: '男' };

    // 混入式
    for (var k in obj1) {
        obj2[k] = obj2[k];
    }


    console.log(obj2);



</script>

</html>